Marine propulsion systems, intake air systems for marine propulsion systems, and marine propulsion systems having exhaust gas relief outlet

ABSTRACT

A marine propulsion system is for propelling a marine vessel in water. The system comprises a marine vessel and an outboard motor that is coupled to the marine vessel. The outboard motor has a first inlet that receives intake air for combustion. A second inlet is located on the hull of the marine vessel and a conduit conveys the intake air from the second inlet on the marine vessel to the first inlet on the outboard motor. The system comprises an outboard motor that is coupled to a marine vessel, and that comprises an exhaust gas relief outlet that is located above the water when the outboard motor is at idle speed. A conduit conveys exhaust gas from the exhaust gas relief outlet to a discharge outlet located on the marine vessel.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present utility application is a continuation-in-part of U.S. patent application Ser. No. 13/605,425, filed Sep. 6, 2012, and a continuation-in-part of U.S. patent application Ser. No. 13/594,547, filed Aug. 24, 2012, both of which are incorporated herein by reference in entirety. U.S. patent application Ser. No. 13/605,425 claims the benefit of and priority to U.S. Provisional Patent Application No. 61/622,614, filed Apr. 11, 2012, which also is incorporated herein by reference in entirety.

FIELD

The present disclosure relates to marine propulsion systems and particularly to intake air systems for marine propulsion systems and exhaust systems for marine propulsion systems.

BACKGROUND

U.S. Patent Application Publication No. 2012/0028517 discloses a marine vessel including an outboard motor mounting portion provided at a stern of a hull, an outboard motor locating hole provided rearward of the outboard motor mounting portion and near the outboard motor mounting portion and penetrating vertically through the stern, a platform provided rearward of the outboard motor locating hole, and an outboard motor located in the outboard motor locating hole and mounted to the outboard motor mounting portion. This structure enables an occupant of the marine vessel to freely move in a space around the outboard motor on the platform and use the space.

SUMMARY

This Summary is provided to introduce a selection of concepts that are further described below in the Detailed Description. This Summary is not intended to identify key or essential features of the claimed subject matter, nor is it intended to be used as an aid in limiting the scope of the claimed subject matter.

Through research and experimentation, the present inventors have determined that when an outboard motor is partially or entirely enclosed by portions of the marine vessel, such as described in the above referenced patent publication, the enclosure experiences a negative pressure when the vessel is underway, which draws water vapor into the enclosure and, in turn, into engine air inlets on the outboard motor. Moist air that is drawn in under the cowl of the outboard motor condenses on hot engine components and causes mineral/salt deposits to form on the engine, resulting in corrosion and overheating problems. The present disclosure is directed to overcoming these types of problems.

Through research and experimentation, the present inventors also have discovered that marine propulsion systems, such as described in the above referenced patent publication wherein the outboard motor is enclosed, have certain drawbacks. For example, the present inventors have found that exhaust gas emitted by idle relief components on the outboard motors are entrapped in the enclosed space of the outboard motor. This has been found to cause problems such as ingestion of carbon monoxide gas by the outboard motor, negatively affecting combustion performance. Further, carbon monoxide buildup within the enclosure can present dangerous situations for the operators of the vessel. Therefore, through research and experimentation the present inventors arrived at the present inventive concepts for overcoming these problems.

In some examples, a marine propulsion system is for propelling a marine vessel in water. The system comprises a marine vessel and an outboard motor that is coupled to the marine vessel. The outboard motor has a first inlet that receives intake air for combustion. A second inlet is located on the hull of the marine vessel. An intake conduit conveys the intake air from the second inlet on the marine vessel to the first inlet on the outboard motor.

In some examples, a marine propulsion system for propelling a marine vessel in water comprises at least one outboard motor coupled to a marine vessel. The outboard motor comprises an exhaust gas relief outlet that is located above the water when the marine vessel is stationary, the outlet relieving exhaust gas, for example when the marine vessel is idling. An exhaust conduit conveys exhaust gas from the exhaust gas relief outlet to a discharge outlet located on the marine vessel. The outboard motor also comprises a primary exhaust gas outlet that is located vertically lower than the exhaust gas relief outlet on the outboard motor and that discharges exhaust gas to the water. The noted exhaust conduit can be sloped along its length so that water does not stagnate therein.

In other examples, a marine propulsion system for propelling a marine vessel in water comprises a marine vessel; and an outboard motor that is coupled to the marine vessel. The outboard motor has a first inlet that receives intake air for combustion; a second inlet located on the hull of marine vessel; and an intake conduit conveying the intake air from the second inlet on the marine vessel to the first inlet on the outboard motor. The outboard motor has an exhaust gas relief outlet that is located above the water when the outboard motor is at idle speed; and an exhaust conduit conveying exhaust gas from the exhaust gas relief outlet to a discharge outlet located on the marine vessel.

BRIEF DESCRIPTION OF THE DRAWINGS

Examples of marine propulsion systems, intake air systems for marine propulsion systems, and exhaust systems for marine propulsion systems are described with reference to the following figures. In certain instances, the same numbers are used in the figures to reference like features and components.

FIG. 1 is a perspective view looking up at a pair of outboard motors attached to the stern of a marine vessel.

FIG. 2 is a perspective view looking down at one of the outboard motors shown in FIG. 1.

FIG. 3 is a side sectional view of the stern of the marine vessel, showing one of the outboard motors.

FIG. 4 is an exploded view showing components of an intake apparatus for the outboard motor.

FIG. 5 is a view of Section 5-5 taken in FIG. 2.

FIG. 6 is an end view of the intake apparatus.

FIG. 7 is a view of Section 7-7 taken In FIG. 6.

FIG. 8 is an exploded view of an adapter for connecting an intake air conduit to the outboard motor.

FIG. 9 is another view of the adapter connected to the outboard motor.

FIG. 10 is a perspective view looking up at the stern of a marine vessel having a pair of outboard motors.

FIG. 11 is a partial top perspective view of one of the outboard motors.

FIG. 12 is a side sectional view of the outboard motor and stern of the marine vessel.

DETAILED DESCRIPTION OF THE DRAWINGS

In the present disclosure, certain terms have been used for brevity, clearness and understanding. No unnecessary limitations are to be inferred therefrom beyond the requirement of the prior art because such terms are used for descriptive purposes only and are intended to be broadly construed. The different methods and systems described herein may be used alone or in combination with other methods and systems. Various equivalents, alternatives, and modifications are possible within the scope of the appended claims.

FIGS. 1-3 depict a marine propulsion system 10 for propelling a marine vessel 12 in water 14. The system includes the marine vessel 12 and at least one outboard motor 16 that is pivotally coupled to the marine vessel 12. The marine vessel 12 is exemplary and the concepts of the present disclosure can be used with other types of marine vessels. The number and configuration of outboard motors 16 can also vary from that which is shown.

The outboard motors 16 each have a first inlet 18 that receives intake air for combustion by its internal combustion engine 20 (see FIG. 5). A second inlet 22 (see FIG. 1) is located on the body 24 of the marine vessel 12 for receiving the intake air. A conduit 26 conveys the intake air from the second inlet 22 on the marine vessel 12 to the first inlet 18 on the outboard motor 16. The second inlet 22 is shown on the starboard side of the marine vessel 12; however it will be recognized by those having ordinary skill in the art that the second inlet 22 can be located on either or both of the port and starboard sides of the marine vessel 12.

As shown in FIGS. 1-3, each outboard motor 16 is at least partially enclosed by the marine vessel 12 in an outboard motor enclosure 32 in a manner such that portions of the marine vessel 12 at least partially surround all sides of the outboard motor 16 that are above waterline 28. Optionally, a hatch can be provided at location 30 or at another location to provide access to the outboard motor 16.

In the example shown, the conduit 26 includes a flexible hose extending from the second inlet 22 to the first inlet 18. In this arrangement, operation of the outboard motor 16 creates a negative pressure in the enclosure 32, which advantageously does not negatively affect pressure of the intake air received by the second inlet 22. As shown in FIGS. 2 and 3, the conduit 26 extends through an engine well 34 and then to the second inlet 22 located on the body 24 of the marine vessel 12.

Referring to FIGS. 4 and 5, the first inlet 18 is connected to an intake manifold 36 that distributes intake air for combustion and also for cooling the outboard motor 16. The manifold 36 is defined by a top cowl 38, an air intake duct 40 and a rear cowl 42. Further, a lower air intake tray 44 is provided on the top cowl 38 for deflecting intake air downwardly as shown at arrow 47 (see FIG. 5) for combustion in the outboard motor 16. Specifically, the lower air intake tray 44 and top cowl 38 define a pair of rear air inlet holes 46 (see FIG. 4) for receiving the intake air. Deflector walls 48 are angled with respect to air flow in the manifold 36 deflect the noted intake air into the inlet holes 46 as shown in FIG. 5.

As air enters the manifold 36 a front air inlet hole 50 in the top cowl 38 receives intake air and distributes the intake air downwardly as shown at arrow 52 (see FIG. 5) for cooling the outboard motor. A fly wheel cover 54 is disposed beneath the intake manifold 36 and has at least one air inlet slit or hole 56 receiving the intake air from the front air inlet hole 50 in the manifold 36. As shown in FIG. 5, the noted rear air inlet holes 46 are located aft of the front air inlet hole 50 on the outboard motor 16.

Referring to FIGS. 4-9, an adapter 70 connects the conduit 26 to the outboard motor 16. The adapter 70 is configured to engage with the outboard motor 16 in a removable, snap-fit connection. In the example shown, the first inlet 18 includes an opening 72 on the air intake duct 40 that receives the adapter 70. The opening 72 is sized slightly larger than an outer diameter of an end 71 of the adapter 70, such that the end 71 can be received by the opening 72. The opening 72 includes diametrically opposed channels 74 for receiving corresponding diametrically opposed protrusions 78 on the adapter 70. A flexible appendage 76 on one side of the end 71 of adapter 70 carries one of the protrusions 78. The appendage 76 is flexible in a radially inward direction, as shown at arrow A to allow the protrusion 78 thereon to be received by corresponding channel 74. As described herein below, the appendage 76 radially flexes back outwardly due to the natural resiliency of the appendage 76 so as to engage the air intake duct 40 in the noted snap-fit connection.

The end 71 of adapter 70 is inserted into the opening 72, as shown at arrows B, so that the protrusions 78 are aligned with the channels 74. The appendage 76 is manually flexed radially inwardly as shown at arrow A to allow the diametrically opposed protrusions 78 to fit within channels 74. Once the protrusions 78 reach the inside end 77 of channels 74, the adapter 70 is manually rotated with respect to the opening 72, as shown at arrows C in FIG. 9, until the protrusion 78 on the appendage 76 becomes aligned with opening 80, at which point the natural resiliency of the appendage 76 moves the appendage 76 radially outwardly so that the protrusion 78 thereon extends into the opening 80 in the radially outward direction, thus engaging the adapter 70 with the air intake duct 40 in the noted snap-fit connection. To remove the adapter 70, a tool can be manually inserted into the opposite end of the opening 80 to force the appendage 76 and its protrusion 78 radially inwardly, as shown at arrow D, at which point adapter 70 is free to be manually rotated opposite to the direction of arrows C and then axially removed from the opening 72 in the direction opposite arrows B. An opposite end 75 of the adapter 70 is threaded for engaging with the conduit 26 in a threaded connection.

As shown in FIG. 4, an air filter 82 can he connected to the conduit 26 for filtering air flow there through. The location and type of air filter 82 can vary from that which is shown.

FIGS. 10-12 depict a marine propulsion system 110 for propelling a marine vessel 112 in water. The system 110 includes a pair of outboard motors 114 that are pivotally coupled to the stern 116 of the marine vessel 112, as is conventional. The concepts of the present disclosure are applicable to other types of marine vessels than what is shown in the FIGURES. Also, the number and configuration of the outboard motors 114 can vary from that which is shown. Each outboard motor 114 is enclosed by a portion of the marine vessel 112. In this example, each outboard motor 114 is enclosed in an engine housing 118 that partially or entirely surrounds all sides of the outboard motor 114 that are located above the waterline 117 when the marine vessel 112 is in the water. In this example, as shown in FIG. 12, the engine housing 118 is located at the stern 116 of the marine vessel 112 and provides a swimming platform 120 for a swimmer to move about the stern 116 without interference from the outboard motor 114.

As shown in FIG. 12, each outboard motor 114 has an internal combustion engine 122 that emits exhaust gases in a conventional manner. Each outboard motor 114 has an exhaust gas relief outlet 124 located above the waterline 117 for relieving exhaust gas when, for example, the engine 122 is at idle. The exhaust gas relief outlet 124 can be located on the back of the engine 122, or other locations. As explained further herein below, a flexible conduit 126 conveys exhaust gas from the exhaust gas relief outlet 124 to a discharge outlet 128 located on the marine vessel 112. Each outboard motor 114 also includes a primary exhaust outlet 130 located in the propeller housing 132, which is positioned vertically lower than the exhaust gas relief outlet 124 and which discharges exhaust gas directly to the water. The location of the respective relief outlet 124 and primary exhaust outlet 130 can vary from that which is shown.

As shown in FIGS. 10-12, the conduit 126 includes a flexible hose that extends from the exhaust gas relief outlet 124 through the forward side of the outboard motor 114 (at 136) and then extends through an engine well 138 (at 140) and then to the discharge outlet 128 on the hull 144 of the marine vessel 112. The flexible hose 126 can be connected at locations 128, 136 and 140 by quick-connect fittings or fixed fittings such as a barb with a clamp. In the depicted arrangement, the location 140 at which the conduit 126 extends through the engine well 138 is located vertically higher than the exhaust gas relief outlet 124 and vertically higher than the discharge outlet 128. This positional relationship has been found by the present inventors to provide certain advantages. In addition to exhaust gas, water is often exhausted out of the internal combustion engine 122. Positioning the conduit 126 at elevated location 140 helps prevent water from remaining in the flexible conduit 126 where, for example, the water can freeze in cold environments. Moisture in the conduit 126 can drain either to the discharge outlet 128 or back into the internal combustion engine 122, which is acceptable. Within these concepts, other portions of conduit 126 can be positioned at relative elevations to allow gravity to drain water out of the flexible conduit 126. The location of discharge outlet 128 can vary from that which is shown and can be on either or both of the port or starboard sides of the hull 144. The conduit 126 can be continuously sloped and devoid of low spots along the length of the conduit where water would otherwise stagnate. This avoids the problems discussed above. The flexible nature of the conduit 126 advantageously allows movement of the outboard motor 114 with respect to the engine well 138, for example during tilting, trimming or rotational movement of the outboard motor 114.

A muffler 146 is located on the engine well 138, internally of the hull 144 and is for decreasing idle relief noise. The muffler 146 can instead, optionally be attached to the outboard motor 114.

FIGS. 1-12 thus depict a boat generally indicated as 12, 112 including a hull generally indicated as 144. The boat 12, 112 includes outboard motors indicated as 16, 114 and a corresponding propeller disposed within a corresponding motor compartment 32, 118 including an air flow system 10 as described hereinabove to supply air to the outboard motors 16, 114 and vent exhaust gases when at idle, each at the aft portion of the hull 144 of the boat 12, 122. Each motor compartment 32, 118 is cooperatively formed between a center mid-ship console, a substantially vertical rear bulkhead, a corresponding hull side extension rearwardly projecting from each side of the stern 116 (all shown in FIGS. 1, 10) and a hatch 30 extending between the hull side extensions to virtually enclose the motor housing 32, 118.

As best shown in FIGS. 3 and 10, each outboard motor 16, 114 is mounted within the corresponding motor compartment 32, 118 by a conventional motor positioning assembly coupled to the stern 116 to independently pivot each outboard motors 16, 114 vertically on a corresponding substantially horizontal pivot (shown in FIGS. 3 and 12) between a substantially vertical position, and an inclined or tilted position and a rotational subassembly to rotate the outboard motors 16 on a corresponding substantially vertical rotation axis to steer the boat 12, 112, as is conventional. The pivot trim subassembly and the rotational subassembly may comprise existing state of the art devices incorporating drive motors, cylinders or screws and cables.

Since each outboard motor 16, 114 is virtually enclosed within the corresponding motor compartment 32, 118, the invention further includes an air flow system 10 to direct the flow of air to each motor compartment 32, 118 during operation of the corresponding outboard motor 16, 114 and an idle exhaust system 110 to direct the flow of exhaust gases from each motor compartment 32, 118 when the corresponding outboard motor 16, 114 is at idle. The air flow system 10 comprises an air intake portion in each motor compartment 32, 118 to feed fresh air from the environs to the air intake of each outboard motor 16. The idle exhaust system 110 comprises an exhaust gas portion in each motor compartment 32, 118 to discharge exhaust gases from the exhaust of each outboard motor 16, 114 into the environs when the corresponding outboard motor 16, 114 is idling or at idle.

Each air intake portion comprises a flexible air intake hose or conduit 26 coupled between the side of the hull 114 of the boat 12, 112 and an air supply intake 36 attached to the outboard motors 16, 114 to feed air from the environs through the flexible air intake hose or conduit 26 and the air supply intake 36 into the corresponding outboard motor 16, 114 through the corresponding air intake 36.

Each idle exhaust system 110 comprises a flexible gas outlet hose or conduit 126 coupled to the corresponding outboard motors 16, 114 over the corresponding exhaust gas outlet 124 and a corresponding exhaust gas discharge port 128 formed in the hull 144 or the boat 12, 112 to discharge exhaust gases from the exhaust gas outlet 124 through the flexible gas outlet hose or conduit 126 and exhaust gas discharge port 128 into the environs.

The present disclosure thus provides an air flow system to direct the flow of air to the engine of the outboard motor during operation thereof and an idle exhaust system to direct the flow of exhaust gases generated by the engine of the outboard motor from the motor compartment when the engine of the outboard is at idle while permitting the outboard motor to be trimmed or tilted about a substantially horizontal axis and rotated about a substantially vertical axis for directional control of the boat. The air flow system comprises an air take portion disposed in said engine compartment to feed fresh air from the environs to the air intake of the engine of the outboard motor and said idle exhaust system comprises an exhaust gas portion disposed in said engine compartment to discharge exhaust gases from the exhaust outlet of the engine of the outboard motor into the environs when the engine of the outboard motor is operating at idle. The air intake portion comprises an air intake conduit coupled between an air inlet or air scoop attached to the boat and an air supply intake attached to the engine of the outboard motor to feed air from the environs into said air intake or air scoop through said air intake conduit and said air supply intake into the engine of the outboard motor through the air intake. The exhaust gas portion comprises a gas outlet conduit coupled between an exhaust gas outlet coupler attached to the exhaust gas outlet of the engine of the outboard motor and an exhaust gas discharge housing or port attached to the boat to discharge exhaust gases from the exhaust gas outlet through said exhaust gas outlet coupler, said flexible gas outlet hose and said exhaust gas discharge housing into the environs when the outboard motor is idling. The air intake conduit and gas outlet conduit each comprises a flexible hose permitting the outboard motor and engine to be trimmed or tilted about a substantially horizontal axis an rotate about a substantially vertical axis. The engine compartment is cooperatively formed between a midship console disposed between the two outboard motors, a rear bulkhead, a hull side extension projecting rearwardly from each side of the stern and a hatch extending between said hull side extensions. The hatch is pivotally coupled to the stern of the boat movable between an open and closed position to permit access to the upper portion of the outboard motor when in the open position.

Although only a few example embodiments have been described in detail above, those skilled in the art will readily appreciate that many modifications are possible in the example embodiments without materially departing from this invention. Accordingly, all such modifications are intended to be included within the scope of this disclosure as defined in the following claims. In the claims, means-plus-function clauses are intended to cover the structures described herein as performing the recited function and not only structural equivalents, but also equivalent structures. Thus, although a nail and a screw may not be structural equivalents in that a nail employs a cylindrical surface to secure wooden parts together, whereas a screw employs a helical surface, in the environment of fastening wooden parts, a nail and a screw may be equivalent structures. It is the express intention of the applicant not to invoke 35 U.S.C. §112, paragraph 6 for any limitations of any of the claims herein, except for those in which the claim expressly uses the words “means for” together with an associated function. 

What is claimed is:
 1. A marine propulsion system for propelling a marine vessel in water, the system comprising: a marine vessel; an outboard motor that is coupled to the marine vessel and has a first inlet that receives intake air for combustion; a second inlet located on the hull of marine vessel; an intake conduit that conveys the intake air from the second inlet on the marine vessel to the first inlet on the outboard motor; wherein the outboard motor has an exhaust gas relief outlet that is located above the water when the outboard motor is at idle speed; and an exhaust conduit conveying exhaust gas from the exhaust gas relief outlet to a discharge outlet located on the marine vessel.
 2. The system according to claim 1, wherein the second inlet extends through one of a port and a starboard side of the marine vessel.
 3. The system according to claim 1, wherein the outboard motor is enclosed by the marine vessel.
 4. The system according to claim 3, wherein the marine vessel at least partially surrounds all sides of the outboard motor that are above the water.
 5. The system according to claim 4, comprising a hatch providing access to the outboard motor.
 6. The system according to claim 4, wherein operation of the outboard motor creates a negative pressure that does not affect pressure of the intake air received by the second inlet.
 7. The system according to claim 1, wherein the intake conduit comprises a flexible hose.
 8. The system according to claim 1, comprising a primary exhaust gas outlet that is located lower than the exhaust gas relief outlet on the outboard motor and that discharges exhaust gas to the water.
 9. The system according to claim 1, wherein the marine vessel comprises a hull and wherein the discharge outlet is on the hull.
 10. The system according to claim 9, wherein the exhaust conduit extends through one of a port and starboard side of the hull.
 11. The system according to claim 10, comprising a muffler receiving exhaust gas from the exhaust conduit.
 12. The system according to claim 11, wherein the muffler is located on the hull.
 13. A marine propulsion system for propelling a marine vessel in water, the system comprising: an outboard motor coupled to a marine vessel, the outboard motor comprising an exhaust gas relief outlet and a primary exhaust gas outlet that is located lower than the exhaust gas relief outlet on the outboard motor and that discharges exhaust gas to the water; and an exhaust conduit conveying exhaust gas from the exhaust gas relief outlet to a discharge outlet located on the marine vessel; wherein the exhaust conduit is sloped along its length so that water does not stagnate therein; wherein the outboard motor has a first inlet that receives intake air for combustion; a second inlet located on the hull of marine vessel; and an intake conduit conveying the intake air from the second inlet on the marine vessel to the first inlet on the outboard motor.
 14. The system according to claim 13, wherein the exhaust conduit extends through the marine vessel at a location that is higher than the exhaust gas relief outlet and higher than the discharge outlet.
 15. The system according to claim 13, wherein the outboard motor is at least partially enclosed by a portion of the marine vessel.
 16. The system according to claim 15, wherein the portion of the marine vessel is an engine housing that surrounds all sides of the outboard motor that are above the water.
 17. The system according to claim 13, wherein the exhaust conduit comprises a flexible hose.
 18. The system according to claim 13, wherein the intake conduit comprises a flexible hose.
 19. In a marine propulsion system having an outboard motor coupled to a marine vessel for propelling the marine vessel in water, an exhaust gas system comprising an exhaust gas relief outlet that is located above the water when the outboard motor is at idle speed and a conduit conveying exhaust gas from the exhaust gas relief outlet to a discharge outlet located on the marine vessel, and an intake air system comprising a first inlet that receives intake air for combustion, a second inlet located on the hull of marine vessel, and an intake conduit conveying the intake air from the second inlet on the marine vessel to the first inlet on the outboard motor.
 20. The system according to claim 19, wherein the marine vessel comprises a hull, wherein the discharge outlet is on the hull, and wherein the second inlet extends through one of a port and a starboard side of the marine vessel. 